Flow structure and mixing characteristics in a stirred tank with dual wide paddle impeller were examined using computational fluid dynamics (CFD). CFD was conducted using analysis code for fluid flow, and velocity measured by laser doppler velocimeter, power consumption and mixing time were used for evaluating computed results. The computed flow field and power consumption agreed well with themeasured values within 5% deviations. Although mixing time had a slight discrepancy between computed and measured ones, its mixing process well agreed with the observations. Since the computed flow pattern and mixing process agreed well with the measured values, computed results are useful for evaluating complex flow field in a stirred tank. A detailed investigation using computed results shows that dual cross-installed wide paddle impellers lead to superior mixing performance in the stirred tank, and pressure gradient between upper and lower paddles is found to be the factor that promotes fluid transport in the tank, which is never the case when the dual wide paddles are installed in the same plane.